Emergency lights of the type used on emergency vehicles such as fire trucks, police cars, motorcycles, snow plows, highway maintenance vehicles, dump trucks and/or ambulances, utilize warning signal lights to produce a variety of light signals. These light signals may involve the use of various colors and patterns. Generally, these warning signal lights in the past have been formed of incandescent and halogen light sources having reflective back support members and colored filters.
Many problems exist with the known methods for producing warning light signals. One particular problem with known light sources is their reliance on mechanical components to revolve or oscillate the lamps to produce the desired light signal or lighting effect. Additionally, these components increase the size of the light support which may adversely affect the vehicles aerodynamic characteristics. Moreover, because of the relatively poor reliability of conventional lighting, and the complexity of the present strobe rotational systems, there is an increased likelihood that a breakdown of the light source will occur, requiring the repair or replacement of the defective component. Finally, conventional light sources require a relatively large amount of electrical current during operation. The demands upon the electrical power system for a vehicle may therefore exceed available electrical resources, reducing optimization of performance or worse, generating a potential hazard from shorted or over heated systems.
Halogen lamps or gaseous discharge xenon lamps generally emanate large amounts of heat which is difficult to dissipate from a sealed light enclosure or emergency light and which may damage the electronic circuitry contained therein. In addition, these lamps consume large amounts of current requiring a large power supply, battery, or electrical source which may be especially problematic for use with a vehicle. These lamps also generate substantial electromagnetic emissions which may interfere with radio communications for a vehicle. Finally, these lamps, which are not rugged, have relatively short life cycles necessitating frequent replacement.
Another problem with the known warning signal lights is the use of filters to produce a desired color. Filtering techniques produce more heat that must be dissipated. Moreover, changing the color of a light source requires the physical removal of the filter from the light source or emergency light and the replacement with a new filter. Furthermore, filters fade or flake over time rendering the filters unable to consistently produce a desired color for observation in an emergency situation.
These problems associated with traditional signaling lamps are exacerbated by the fact that creating multiple light signals requires multiple signaling lamps. Further, there is little flexibility in modifying the light signal created by a lamp. For example, changing a stationary lamp into one that rotates or oscillates would require a substantial modification to the light support which may not be physically or economically possible.
The present invention generally relates to electrical lamps and to high brightness light-emitting diode or “LED” technology which operates to replace gaseous discharge or incandescent lamps as used with vehicle warning signal light sources.
Another problem with the known warning signal lights is the use of rotational and/or oscillating mechanisms which impart rotational or oscillating movement to a light source for observation during emergency situations. These mechanical devices are frequently cumbersome and difficult to incorporate and couple onto various locations about a vehicle due to the size of the device. These mechanical devices also frequently require a relatively large power source to impart rotational and/or oscillating movement for a light source.
Another problem with the known warning signal lights is the absence of flexibility for the provision of variable or modulated illumination intensity for the light sources to increase the number of available distinct and independent visual light effects. In certain situations it may be desirable to provide variable or modulated illumination intensity for a light signal, for the creation of a unique light effect to facilitate observation by an individual. In addition, the provision of a variable or modulated light intensity for a light signal may further enhance the provision of a unique desired light effect for observation by an individual.
Current end cap warning signal assemblies are generally limited to light signals produced by rotational and/or oscillating mechanisms which impart rotational or oscillating movement to a light source for observation during emergency situations.
In view of the above, there is a need for an end cap warning signal assembly that:                (1) Is capable of producing the appearance of a rotating warning light signal without reliance upon mechanical components;        (3) Generates little heat;        (4) Uses substantially less electrical current;        (5) Produces significantly reduced amounts of electromagnetic emissions;        (6) Is rugged and has a long life cycle;        (7) Produces a truer light output color without the use of filters;        (8) Provides variable or modulated light intensity to the light source.        
The ease of visualization of an emergency vehicle is a primary concern to emergency personnel regardless of the location of the observer. In the past, optimal observation of emergency lights has occurred when an individual was either directly in front of, or behind, an emergency vehicle. Observation from the sides, or at an acute angle relative to the sides, frequently resulted in reduced observation of emergency lights during an emergency situation. A need therefore exists to improve the observation of emergency lights for a vehicle regardless of the location of the observer. A need also exists to improve the flexibility of placement of emergency lights upon a vehicle for observation by individuals during emergency situations.
A need exists to reduce the size of light supports on an emergency vehicle and to improve the efficiency of the light sources particularly with respect to current draw and reduced aerodynamic drag. In addition, the flexibility for the positioning of the light sources about a vehicle for observation by individuals is required to be enhanced in order to optimize utility for a warning signal light. In order to satisfy these and other needs, more spatially efficient light sources such as LEDs are required.